This invention relates generally to manipulating virtual objects in a modeling environment. More particularly, the invention relates to the selection and manipulation of three-dimensional objects represented in a two-dimensional display space.
Systems and methods for selecting and manipulating objects in computer-based modeling environments are known. Examples of existing systems that select and manipulate objects include circuit board design systems and systems used for designing mechanical objects, such as automobiles and airplanes. Some systems typically impose restrictions on a user, such as placing objects such as circuit elements on predefined planes. Other systems require a user to specify a location of a component with high precision in three dimensions and three angular orientations. The devices commonly used for providing information to the modeling system include alphanumeric input devices, such as keyboards, and cursor-based devices operating in two dimensions, such as computer mice and trackballs. Present computer-based modeling systems generally do not permit a user to readily modify an object that has been selected.
The stringent rules that present computer-based modeling systems impose and the inability of users to select, manipulate, and modify objects in a manner more akin to natural motion limits the ability of users to create models of three-dimensional objects.
The systems and methods of the invention provide a user the ability to select three-dimensional virtual objects in a three-dimensional modeling environment using two-dimensional representations of the objects. In broad overview, the invention involves a multidimensional degree of freedom haptic interface that controls a three-dimensional cursor. A user employs the cursor to select an arbitrary point on a three-dimensional virtual object on interest. The user can select the object by positioning the cursor so-as to coincide with a point of the object in two of three dimensions, and issuing a select command. Through the application of a mathematical transformation, the system determines the difference between the position of a selected point on the object and the position of the cursor. The system displays the cursor at the location of the selected point on the object, so that the user can more easily manipulate or edit the object in the modeling environment. When the user releases the object after manipulation is completed, the cursor is relocated to the position it would have had the manipulations been applied to the cursor directly.
In one embodiment, the invention features a method for selecting an object in a three-dimensional modeling environment. The method includes the steps of generating a three-dimensional modeling environment containing one or more virtual objects and a three-dimensional cursor, determining a first three-dimensional cursor position in the three dimensional modeling environment, the three-dimensional cursor position corresponding to a position of an input device having at least three degrees of freedom, representing a first view of at least one of the one or more virtual objects in a first two-dimensional display space, representing the three-dimensional cursor position in the two-dimensional display space, and selecting one of the virtual objects based on a positional correspondence of the object and the cursor in the two-dimensional display space.
In some embodiments, the input device has at least six degrees of freedom. In one embodiment, the input device has exactly six degrees of freedom. In some embodiments, the virtual object is a selected one of a point, a straight line segment, a curvilinear segment, a spline, a two-dimensional representation, and a three dimensional representation.
In some embodiments, the method further includes the step of editing the selected virtual object. In some embodiments, editing the selected virtual object is a selected one of coloring the object, modifying the object, combining the object with another virtual object, grouping the object with another object, deleting the object, and renaming the object. In some embodiments, editing the selected virtual object includes sculpting the selected virtual object.
In some embodiments, the method further includes the step of performing a file function involving the selected virtual object. In some embodiments, performing a file function includes saving the object to a file.
In some embodiments, representing a first view of at least one of the one or more virtual objects includes representing the one or more virtual objects in a selected one of a perspective view and an orthogonal view.
In some embodiments, the method further includes the steps of selecting a local origin point on the selected virtual object and defining a mathematical transformation in the three-dimensional modeling environment, the mathematical transformation representative of the difference in location of the local origin point and the three-dimensional cursor position.
In some embodiments, the local origin point is an arbitrary point on the object. In some embodiments, defining the mathematical transformation includes defining a vector having a component directed orthogonal to the two-dimensional display space. In some other embodiments, defining the mathematical transformation includes defining a mathematical transformation having at least one of a three-dimensional translational vector, a rotation about the local origin point, and a rotation about the three-dimensional cursor position.
In some embodiments, the method further includes the steps of applying the transformation and manipulating the virtual object, the manipulation of the virtual object corresponding to a manipulation of the input device by the user.
In some embodiments, the method further includes the step of manipulating the virtual object, the manipulation of the virtual object corresponding to a manipulation of the input device by the user combined with an application of the transformation. In some embodiments, the manipulation of the input device includes at least one of a translational degree of freedom and a rotational degree of freedom. In some embodiments, the manipulation of the input device includes a simultaneous manipulation of two or more independent degrees of freedom. In some embodiments, the manipulation of the input device includes a simultaneous manipulation of three or more independent degrees of freedom. In some embodiments, the manipulation of the input device includes a simultaneous manipulation of six or more independent degrees of freedom.
In some embodiments, the method further includes the step of relocating the three-dimensional cursor to the location of the local origin point by application of the mathematical transformation. In some embodiments, the relocating step is performed only during the duration of the manipulation.
In some embodiments, the method further includes the step of providing a visual aid to help the user select and manipulate the virtual object. In some embodiments, providing the visual aid includes providing a user-activated constraint limiting a point to a locus aligned to an axis of the three-dimensional modeling environment.
In some embodiments, the method further includes the step of moving the three dimensional cursor to a position it would have if the manipulation of the input device by the user had been applied directly to the three dimensional cursor. In some embodiments, the moving step is performed upon a command issued by the user. In some embodiments, the command is a release of the selected virtual object.
In some embodiments, the method further includes the step of providing a visual aid to help the user select and manipulate the virtual object. In some embodiments, providing the visual aid includes providing a user-activated constraint limiting a point to a locus aligned to an axis of the three-dimensional modeling environment. In some embodiments, providing the visual aid includes providing a context-specific visual aid consistent with user-defined geometrical limitations. In some embodiments, providing the visual aid includes representing a second view of at least one of the one or more virtual objects in a second two-dimensional display space, the first two-dimensional display space and the second two-dimensional display space corresponding to different-planes of the three-dimensional modeling environment. In some embodiments, representing the second view includes representing the second view on the second two-dimensional display space whose plane is orthogonal to a plane of the first two-dimensional display space.
In some embodiments, the input device is a hap tic device. In some embodiments, the haptic device includes a haptic device providing force feedback to actuators operating in at least three degrees of freedom.
In some embodiments, the method further includes the step of providing a haptic aid to help the user select and manipulate the virtual object. In some embodiments, the haptic aid includes the provision of dynamic friction force during the positional correspondence of the object and the cursor in the two-dimensional display space. In some embodiments, during an activation of the user-activated visual constraint limiting a point to a locus aligned to an axis of the three-dimensional modeling environment, the haptic aid includes a haptic constraint limiting motion of the three-dimensional cursor to directions aligned to an axis of the three dimensional environment, except within a region of radius R about an identified point.
In some embodiments, the method further includes the step of contemporaneously displaying a visual aid component that indicates an axial location of the cursor along an axis. In some embodiments, during an activation of the user-activated visual constraint limiting a point to a selected line, the haptic aid includes a haptic constraint limiting motion of the three-dimensional cursor to the line.
In some embodiments, the method further includes the step of contemporaneously displaying a visual aid component that indicates the location of an axial location of the cursor along an axis. In some embodiments, during an activation of the user-activated visual constraint limiting a point to a selected plane, the haptic aid includes a haptic constraint limiting motion of the three-dimensional cursor to the plane.
In some embodiments, the method further includes the step of contemporaneously displaying a visual aid component that indicates the location of the plane.
In one aspect, the invention relates to an apparatus that permits a user to select an object in a three-dimensional modeling environment. The apparatus includes a computer that supports a three-dimensional modeling environment application, an input device that provides user input to the computer, the input device having at least three degrees of freedom, a modeling module that, when operating, generates the three-dimensional modeling environment using the computer, the three-dimensional modeling environment adapted to model one or more virtual objects and to employ a three-dimensional cursor, and a selection module responsive to user commands that, when operating, selects one of the virtual objects based on a two-dimensional positional correspondence of the object and the cursor.
In some embodiments, the apparatus further includes a display device that provides a two-dimensional display space for presenting to the user representations of the virtual object and the three-dimensional cursor in the modeling environment.
In some embodiments, the apparatus further includes a rendering module that, when operating, renders on the display device a view of the virtual object in a selected one of a perspective view and an orthogonal view. In some embodiments, the input device has at least six degrees of freedom. In one embodiment, the input device has exactly six degrees of freedom. In some embodiments, the virtual object is a selected one of a point, a straight line segment, a curvilinear segment, a spline, a two-dimensional representation, and a three dimensional representation.
In some embodiments, the apparatus further includes an editing module that, when operating, edits the selected virtual object in response to user input. In some embodiments, the editing module is a selected one of a module that sculpts the object, a module that colors the object, a module that modifies the object, a module that combines the object with another virtual object, a module that groups the object with another object, a module that deletes the object, a module that renames the object, and a module that performs a file function involving the object.
In some embodiments, the apparatus further includes a cursor tracking module that, when operating, determines a position of the three-dimensional cursor in the three dimensional modeling environment, the position of the cursor corresponding to a position of the input device, an object tracking module that, when operating, tracks a local origin point on the selected virtual object, and a transformation module that, when operating, defines a mathematical transformation in the three-dimensional modeling environment, the mathematical transformation representative of a difference in location of the local origin point and the three-dimensional cursor position at a time the user selects the virtual object. In some embodiments, the transformation module defines the mathematical transformation in terms of at least one of a three-dimensional translational vector, a rotation about the local origin point, and a rotation about the three-dimensional cursor position.
In some embodiments, the apparatus further includes an object manipulation module that, when operating, manipulates the virtual object, the manipulation of the virtual object corresponding to a manipulation of the input device by the user combined with an application of the transformation. In some embodiments, the object manipulation module represents the manipulation of the input device using at least one of a translational degree of freedom and a rotational degree of freedom. In some embodiments, the object manipulation module is adapted to manipulate at least two independent degrees of freedom simultaneously. In some embodiments, the object manipulation module is adapted to manipulate at least three independent degrees of freedom simultaneously. In some embodiments, the object manipulation module is adapted to manipulate at least six independent degrees of freedom simultaneously.
In some embodiments, the apparatus further includes a relocation module that, when operating, relocates the three-dimensional cursor to the location of the local origin point by application of the mathematical transformation. In some embodiments, the relocation module is operative only during the duration of the manipulation.
In some embodiments, the apparatus further includes a visual aid module that, when operating, provides a visual aid to help the user select and manipulate the virtual object. In some embodiments, the visual aid module is responsive to a user command, the visual aid module constraining a display of a point manipulated by a user to a locus aligned to an axis of the three-dimensional modeling environment.
In some embodiments, the apparatus further includes a cursor repositioning module that, when operating, moves the three dimensional cursor to a position it would have if the manipulation of the input device by the user had been applied directly to the three dimensional cursor. In some embodiments, the cursor repositioning module operates in response to a command issued by the user. In some embodiments, the command is a release of the selected virtual object.
In some embodiments, the apparatus further includes a visual aid module that, when operating, provides a visual aid to help the user select and manipulate the virtual object. In some embodiments, the visual aid module is responsive to a user command, the visual aid module constraining a display of a point manipulated by a user to a locus aligned to an axis of the three-dimensional modeling environment. In some embodiments, the visual aid module is responsive to a user command, the visual aid module constraining a display of a point manipulated by a user to a locus consistent with user-defined geometrical limitations. In some embodiments, the visual aid module represents a second view of at least one of the one or more virtual objects in a second two-dimensional display space, the first two-dimensional display space and the second two-dimensional display space corresponding to different planes of the three-dimensional modeling environment. In some embodiments, the visual aid module represents the second view on the second two-dimensional display space whose plane is orthogonal to a plane of the first two-dimensional display space.
In some embodiments, the input device is a haptic device. In some embodiments, the input device is a haptic device having force feedback actuators operating in at least three degrees of freedom to apply force to the user.
In some embodiments, the apparatus further includes a haptic aid module to help the user select and manipulate the virtual object. In some embodiments, the haptic aid module computes a dynamic friction force to be applied to the user by way of the haptic device during a positional correspondence of the object and the cursor in two dimensions of the three-dimensional modeling environment. In some embodiments, during an activation of the user-activated. visual constraint limiting a point to a locus aligned to an axis of the three-dimensional modeling environment, the haptic aid module activates the force feedback actuators to provide haptic force to the user upon deviation of the point from the locus. In some embodiments, the visual aid module is additionally adapted to display a visual aid component that indicates a location of the cursor along an axis. In some embodiments, during an activation of the user-activated visual constraint limiting a point to a selected line, the haptic aid module activates the force feedback actuators to provide haptic force to the user upon deviation of the point from the line. In some embodiments, the visual aid module is additionally adapted to display a visual aid component that indicates a location of the cursor along a line. In some embodiments, during an activation of the user-activated visual constraint limiting a point to a selected plane, the haptic aid module activates the force feedback actuators to provide haptic force to the user upon deviation of the point from the plane. In some embodiments, the visual aid module is additionally adapted to display a visual aid component that indicates a location of the cursor on a plane.